At present, the requirements on portable electronic devices by consumers tend to thin-type day by day, and thus the electronic components in the electronic devices tend to thin-type day by day. Wherein, a loudspeaker unit, as an important acoustic element, tends to thin-type day by day as well. The loudspeaker comprises a vibrating diaphragm for radiating sound. As the difference between the phases of sounds radiated to the front side and the rear side of the vibrating diaphragm is 180 degree, the front acoustic cavity and the rear acoustic cavity should be mutually spaced. In order to avoid defects, such as, the front acoustic cavity being not spaced from the rear acoustic cavity completely, due to installing the loudspeaker unit in the electronic device directly, typically, the loudspeaker unit is provided in a peripheral frame in advance to form a loudspeaker module, and form a closed rear acoustic cavity and a front acoustic cavity only in communication with a sound outlet hole, and then the loudspeaker module is installed in the electronic device.
However, as electronic devices tend to thin-type day by day, the thickness of the loudspeaker module is limited strictly, and the size of the loudspeaker unit and the size of the acoustic cavity are greatly limited. Thus, the acoustical performance and output power of the loudspeaker module are affected by the loudspeaker units with existing structures to a certain degree. Additionally, there are only simple locational installation and electric connection implementation between the conventional loudspeaker modules and the electronic devices, and the space inside the electronic device is not utilized sufficiently. Accordingly, there is a need to improve the conventional loudspeaker modules and the electronic devices to balance thin-type and acoustical performance of the product.